Regarding the Gansu school bus tragedy, Kelvin Chan noted the need for mainland authorities to enact and enforce appropriate school bus safety regulations. We need to do this in Hong Kong, too.

Officials at my daughters' primary school have tried for years to get the Transport Department to require seat belts in all Hong Kong school buses. But the department says the cost would be too high.

There is no amount of money I could imagine that I would accept for my daughters' lives. I don't believe there is any amount that the parents of those lost children in Gansu wouldn't give if they could to get their children returned safely to them.

The full cost from the public purse of medical care and rehabilitation for the entire lifetime of children injured in a single severe school bus accident is likely to be many times the cost of getting seat belts installed on all our school buses.

My children ride this bus each school day. I have noted with great concern that there are no seat belts on most of their school's rented buses.

This means that in a side impact the children would be violently hurled from their seats into other children, seats, and stationery objects within their school bus at about the speed the bus is moving (say 50km/h), with the probability of injury and death extremely likely.

The possibility of ejection from the vehicle through windows or doors (even if they are closed) is also high, with the likelihood of a child surviving an ejection from the bus cabin extremely low.

I want a seat belt on every seat on every school bus. I want my daughters and the thousands of other children to be compelled to wear seat belts during their daily trips to and from school.

We do have school bus accidents of varying severity here every year. How many children will have to be badly injured or killed before the Transport Department will require seat belts to be used in all school buses?

We can argue, for example, that buses can't be retrofitted to accept seat belts and that such belts are not suitable for schoolchildren of all ages in all circumstances. But the point remains that children unrestrained by seat belts are more likely to be killed or injured in a school bus accident than if they were properly restrained.